Press maintenance and use

The press is a compact, versatile press. With its versatility and high production efficiency, the press can be widely used in cutting, punching, blanking, bending, riveting and forming processes. The parts are machined by plastically deforming and breaking the metal by applying a strong pressure on the metal blank. When the mechanical press is working, the motor drives the large pulley (usually doubled as the flywheel) through the V-belt and drives the crank slider mechanism through the gear pair and the clutch to make the slider and the punch die go down. After the forging work is completed, the mechanical press moves up and the clutch is automatically disengaged. At the same time, the robot on the crankshaft is turned on, and the slider stops near the top dead center.

The screw press adopts screw and nut as the transmission mechanism, and relies on the screw transmission to transform the forward and reverse rotation of the flywheel into the forging and pressing machine for reciprocating mechanical movement of the slider. During operation, the motor accelerates the flywheel to save energy, while pushing the slider downwards through the screw and nut. When the slider contacts the workpiece, the flywheel is forced to decelerate to a complete stop, the stored rotational kinetic energy is converted into impact energy, and the workpiece is deformed by the slider. After the blow is over, the motor reverses the flywheel, causing the slider to rise and return to its original position. Screw press specifications are expressed in terms of nominal working force.

The crank press is one of the most commonly used cold stamping machines used as a working platform for cold stamping dies. Its structure is simple and easy to use. According to the different structure of the bed, crank presses can be divided into open crank presses or closed crank presses; press the number of drive links can be divided into single or multiple presses; press the number of sliders One or two can be divided into single-acting presses or double-acting presses.

Friction press is a kind of universal pressure processing machine, which is widely used and can be used in various industries of pressure processing. In the machinery manufacturing industry, the application of friction presses is more extensive and can be used to complete the work of die forging, upset forging, bending, correction, coining, etc. Some flashless forgings are also done using this press. Due to the versatility of the use of presses, and the advantages of simple structure, installation, operation and auxiliary equipment, and low cost, press shops, forging shops and die forgings are used in machinery manufacturing, automotive, tractor and aviation industries. The workshops are widely used, and stamping and refractories can also be used for pressing.

The multi-station press is an advanced press machine and is an integration of multiple presses. It is generally composed of a line head unit, a feed mechanism, a press, and a tail section. The fastest tempo up to 25 beats/minute or more can satisfy high-speed automated production. The thread end unit can be divided into unstacking unit, magnetic belt, cleaning and oiling equipment, etc. The feeding mechanism is generally composed of feeding arms; the pressing machine is generally divided into multiple sliders and sliders, which are selected according to different requirements. Generally consists of conveyor belts.

Mechanical Principle Presses are usually driven by the motor to drive the flywheel rim through friction discs, so this type of press is also called a friction press. China's largest friction press is 25 meganewtons. Larger presses use a hydraulic system to drive the flywheel, known as a hydraulic screw press. The largest specification is 125 meganewtons. Then came the electric press that directly driven the flywheel with a motor. It had a compact structure and few transmission links. Due to frequent commutation, it required higher control electronics and required a special motor.

The rotary press has no fixed bottom dead point. For larger die forgings, it can be formed by multiple blows and can be used for singles, consecutive hits and inch moves. The striking force is related to the deformation of the workpiece. When the deformation is large, the striking force is small, and when the deformation is small (such as a cold strike), the striking force is large. In these respects it is similar to a forging hammer. However, its slider speed is low (about 0.5 m/s, which is only 1/10 of the forging hammer), and the striking force is closed by the frame, so the work is smooth and the vibration is much smaller than the forging hammer and does not require a large foundation. The press is equipped with a slip insurance mechanism, which limits the maximum impact force to less than 2 times the nominal pressure to protect the safety of the equipment.

The lower part of the press is equipped with a forging ejector. Screw presses have the functions of various forging machines such as die forging hammers and mechanical presses. They have strong versatility and can be used in die forging, punching, deep drawing and other processes. In addition, screw presses, particularly friction presses, are simple in construction and easy to manufacture, so they are widely used. Screw presses have the disadvantage of lower productivity and mechanical efficiency.

Machines that use improper press operation or press die set-ups cause the press to be the primary cause of damage and downtime. Properly trained press operators and press die setters can ensure that they follow correct procedures. This will quickly reduce downtime.

Before each shift, add lubricant to each brake shaft of the manipulator. Before the daily shift, use a grease gun to fill in the amount of mechanical oil of No. 20-30 before the daily shift. Apply the oil gun to the clutch before the shift every day. . Clean the machine before each stop.

Check fasteners and make up for missing parts. Check clutch and spring, belt. Check the lubrication of the machine tool. Check the electrical circuit for damage, aging, and whether the motor or electromagnet is normal. Check crankshaft guides for accuracy and wear. Check brakes, clutches, slides, closing blocks, closing rings. Check the electrical control section. Fuselage table joint bolt detection and adjustment.

According to the different types of machines and processing requirements of the presses, there are targeted and practical safety operating procedures, and necessary job training and safety education. The users and operators must strictly abide by the regulations and operating procedures of the safety instructions provided by the design and manufacturing company, and use and repair them properly. The general safety operation requirements for presses are as follows:

Before moving the equipment, check whether the operating part of the press, the clutch and the brake are in the valid state, whether the safety protection device is complete and easy to use, and whether there is any abnormality in each part of the crank slider mechanism. Abnormalities should be taken immediately and necessary measures must be taken. They must not be sick and must not be disassembled or damaged. Before the formal operation, the idling test must be performed to confirm that all parts can work normally. Before starting the machine, all unnecessary items on the workbench should be cleaned to prevent people from hitting or knocking on the switch to cause the slider to suddenly start. The tool must be used for operation. It is strictly forbidden to directly enter into the die mouth by hand. The hand tool must not be placed on the mould.

When adjusting the position of the workpiece in the die area or removing the workpiece stuck in the mold, the foot must leave the pedal. Many people operating the same press should have a unified command, clear signal, and the other party should make a clear response, and confirm that they leave the danger zone and move again. After a sudden power failure or after the operation is complete, the power should be turned off and the manipulator returned to clutch neutral. The brake is in braking state. When the press is inspected, adjusted and installed, adjusted, and disassembled, it should be done under the condition that the machine disconnects energy (such as electricity, gas, and liquid) and the machine stops running. Support. A warning is displayed at the start-up switch of the machine tool.

Mechanical maintenance Pay attention to the safety during the maintenance process. Make sure that the locking/opening process is performed correctly to ensure the safety of the maintenance personnel and ensure that the sleeve is placed at the bottom of the stroke before performing brake maintenance work. If this is done, there is no need to lock the sleeve again.

Adding the press operator to the maintenance process to add the press operator to the maintenance press allows them to alert the maintenance or management staff at any time of problems. They perform press operations every day, making it easier to hear or see signs of problems. Just as you drive the same car every day, you can notice abnormal sounds the first time, which is the same for operators.

The workshop environment controls a clean press that allows operators or maintenance personnel to quickly find out when problems occur. Such as oil leaks, leaks, breaks, etc. If the press is clean, it is easy to find out where it is.

A press that is in a balanced position to ensure that the press is in balance can work better, so it is best to check it once a year. Pneumatic systems are responsible for the operation of pneumatic brakes and balancing systems. They need to check for gas leaks, because proper air pressure can affect the performance of the brakes and balancing system, and they control the stopping time of the press. Once a problem occurs, it will cause the operation. And equipment are in danger. In addition, all pneumatic systems have regulators, lubricators and reservoirs. The water accumulated in the gas line should be removed every day.

Changing lubricants and screens over time Improper maintenance of the press lubrication system is also one of the main reasons for press shut downs. For some reasons, many press operators operate on recirculating oil systems with screens. Change the filter occasionally. It should be ensured that the filter is replaced at the same time as the oil is changed, and it must be replaced frequently at ordinary times.

The key to mechanical press maintenance What is the most important aspect of a mechanical press maintenance routine? The answer is the operator. All the press maintenance and problem finding started with the operator, and the operator can often find the press problem early enough to prevent major damage to the press components and continue to damage. Operators can find problems by paying attention to strange sounds from the press; abnormal temperature rises, smoke, debris or metal particles in some parts; and leaking lines. Every day, the operator should ask himself some questions and record and answer after checking to maintain a long-term maintenance record.